Revellers celebrate the winter solstice at Stonehenge on Salisbury Plain in southern England December 22, 2015. Stonehenge is a celebrated venue of festivities during the winter solstice – the shortest day of the year in the northern hemisphere – and it attracts thousands of revellers, spiritualists and tourists. Druids, a pagan religious order dating back to Celtic Britain, believe Stonehenge was a centre of spiritualism more than 2,000 years ago. (Photo by Kieran Doherty/Reuters)

Revellers celebrate the winter solstice at Stonehenge on Salisbury Plain in southern England December 22, 2015. (Photo by Kieran Doherty/Reuters)

A druid celebrates the winter solstice at Stonehenge on Salisbury Plain in southern England December 22, 2015. (Photo by Kieran Doherty/Reuters)

Revellers celebrate the winter solstice at Stonehenge on Salisbury Plain in southern England December 22, 2015. (Photo by Kieran Doherty/Reuters)

A druid holds his sword as he celebrates the winter solstice at Stonehenge on Salisbury Plain in southern England December 22, 2015. (Photo by Kieran Doherty/Reuters)

Revellers celebrate the winter solstice at Stonehenge on Salisbury Plain in southern England December 22, 2015. (Photo by Kieran Doherty/Reuters)

Revellers carry their duvet as they celebrate the winter solstice at Stonehenge on Salisbury Plain in southern England December 22, 2015. (Photo by Kieran Doherty/Reuters)

Revellers meditate as they celebrate the winter solstice at Stonehenge on Salisbury Plain in southern England December 22, 2015. (Photo by Kieran Doherty/Reuters)

Revellers meditate as they celebrate the winter solstice at Stonehenge on Salisbury Plain in southern England December 22, 2015. (Photo by Kieran Doherty/Reuters)

Rollo Maughfling, Archdruid of Stonehenge & Britain (C) conducts a ceremony as druids, pagans and revellers gather in the centre of Stonehenge, hoping to see the sun rise, as they take part in a winter solstice ceremony at the ancient neolithic monument of Stonehenge near Amesbury on December 22, 2015 in Wiltshire, England. Despite a forecast for rain, a large crowd gathered at the famous historic stone circle, a UNESCO listed ancient monument, to celebrate the sunrise closest to the Winter Solstice, the shortest day of the year. The event is claimed to be more important in the pagan calendar than the summer solstice, because it marks the “re-birth” of the Sun for the New Year. (Photo by Matt Cardy/Getty Images)

Susie Ro Prater (C) leads the Shakti Sings choir as druids, pagans and revellers gather in the centre of Stonehenge, hoping to see the sun rise, as they take part in a winter solstice ceremony at the ancient neolithic monument of Stonehenge near Amesbury on December 22, 2015 in Wiltshire, England. (Photo by Matt Cardy/Getty Images)

Two people wearing animal costumes join others as people gather to celebrate the Winter Solstice at Stonehenge in England Tuesday December 22, 2015. The winter solstice is celebrated by many people around the world as the beginning of the return of the sun. (Photo by Ben Birchall/PA Wire via AP Photo)

People gather at Stonehenge in Wiltshire on the Winter Solstice to witness the sunrise on the shortest day of the year on December 22, 2015. The winter solstice is the annual event which marks the point where the North Pole is tilted 23.5 degrees away from the sun. As a result of the north of Earth leaning away from the Sun, Tuesday will see the fewest hours of sunlight in one day. (Photo by Ben Birchall/PA Wire)